[WebAssembly] Fix overflow for input with missing version

Differential revision: https://reviews.llvm.org/D37070

llvm-svn: 311605
diff --git a/llvm/test/Object/wasm-missing-version.test b/llvm/test/Object/wasm-missing-version.test
new file mode 100644
index 0000000..98586e7
--- /dev/null
+++ b/llvm/test/Object/wasm-missing-version.test
@@ -0,0 +1,2 @@
+# RUN: not llvm-objdump -h %p/Inputs/WASM/missing-version.wasm 2>&1 | FileCheck %s
+# CHECK: {{.*}}: Missing version number